A dental abscess occurs when bacteria infect and spread inside a tooth, your gums or the surrounding tissue.

Your mouth is full of bacteria, which combine with small particles of food and saliva to form a sticky film called plaque, which builds up on your teeth. Brushing your teeth helps to stop plaque from building up.

Eating and drinking food and drink high in carbohydrates causes the bacteria in plaque to turn the carbohydrates into the energy they need to reproduce. Acids are then produced, which leads to tooth decay.

Tooth decay can lead to the formation of a dental abscess. This can occur when bacteria spread into:

• the centre of a tooth (the pulp) through tiny holes in the tooth (dental caries) caused by the excess acid – when this spreads under the teeth this is known as a periapical abscess
• your gums and surrounding tissues – this is known as a periodontal abscess

Periapical abscesses

When a periapical abscess develops, plaque bacteria infect your tooth as a result of dental caries, which form in the hard outer layer of your tooth (the enamel).

Dental caries break down the enamel and the softer layer of tissue underneath (dentine), eventually reaching the centre of the pulp. This is known as pulpitis. The dental pulp in the middle of the tooth dies and the pulp chamber becomes infected.

The bacteria continue to infect the pulp until it reaches the bone that surrounds and supports your tooth (alveolar bone), where the periapical abscess forms.

Periodontal abscesses

A periodontal abscess is caused by gum disease (also known as gingivitis or periodontitis).

A periodontal abscess may also occur as a result of:

• gum damage, even if you do not have periodontitis
• smoking and using smokeless tobacco – read more information about quitting smoking

Risk factors

Risk factors for a dental abscess include:

• poor oral hygiene – if you do not brush your teeth and floss regularly, your risk of developing a dental abscess increases
• having a diet high in sweet and sticky food and drink – such as chocolate, sweets, sugar and fizzy drinks and/or starchy foods, such as crisps, white bread, pretzels and biscuits
• having a weakened immune system – this may be because of an underlying health condition, such as diabetes, or the side effects of treatments like steroid medication (corticosteroids) or chemotherapy

Read more about the risks of gum disease.

With the right treatment, a dental abscess is easily cured. However, in rare cases, complications can occur.

Most complications arise due to the spread of the bacterial infection when an abscess is left untreated.

Possible complications are outlined below.

Loss of the tooth

The affected tooth may need to be removed (extracted). This is more likely if a dental abscess returns, or if your tooth is severely broken down.

Sinusitis

Sinusitis is an infection of the small air-filled cavities inside your skull.

It is usually the cavities behind your cheekbones that can become infected as a complication of a dental abscess. These are known as the maxillary sinuses.

Symptoms of sinusitis include:

• a blocked or runny nose
• facial pain and tenderness
• a high temperature (fever) of 38°C (100.4°F) or above

Sinusitis often clears up without treatment but, if necessary, antibiotics can be prescribed.

Read more about sinusitis.

Osteomyelitis

Osteomyelitis is an infection of the bone. It can be caused by the bacteria in a dental abscess spreading and causing inflammation.

Osteomyelitis can cause symptoms such as fever, nausea (feeling sick) and severe pain in the affected bone, which can often be in the area surrounding a dental abscess.

However, as the infection is spread through your blood, it can affect any bone in your body. Osteomyelitis can be treated by taking oral antibiotics or injecting them into a vein.

Read more about osteomyelitis.

Cavernous sinus thrombosis

Cavernous sinus thrombosis is a rare, but serious, condition where a blood vessel in the brain becomes infected and a clot develops.

Read more information about cavernous sinus thrombosis.

Ludwig’s angina

Ludwig’s angina is a potentially life-threatening infection of the tissues of the floor of the mouth, under the tongue.

Symptoms can include:

• swelling
• pain when moving the tongue
• neck swelling
• fever
• difficulty swallowing (dysphagia)
• difficulty breathing

In severe cases, you may have trouble breathing or experience an abnormal breathing sound, caused by a blocked airway.

If you think you may have a dental abscess, see a dentist as soon as possible.

Find a dentist in your local area.

Your dentist will carry out some tests to determine whether your symptoms are being caused by a dental abscess. They may:

• tap on the affected tooth or area of gum – if infection is present, your tooth or gum will be sensitive to any pressure
• examine your gums – an infection will usually cause an area of your gums to become red and swollen
• take an X-ray of the affected area to help assess the spread of infection

In some cases, your dentist may be able to confirm a diagnosis by simply asking about your symptoms.

Your dentist will then discuss the most appropriate treatment.

Referral

Depending on how severe your abscess is, you may be referred for treatment in hospital.

This may happen if you:

• are feeling unwell with a high temperature, a rapid pulse rate or low blood pressure (hypotension) and rapid breathing
• are in severe pain, despite taking painkillers
• have a spreading facial infection
• have a weakened immune system (this could happen if you are having treatment, such as chemotherapy)

A dental abscess is a collection of pus that forms in your teeth and spreads to the surrounding tissue. It forms as the result of a bacterial infection.

The main symptom of a dental abscess is a severe, throbbing pain. The pain usually comes on suddenly, gets gradually worse over a few hours or days, and causes teeth to be tender and sensitive.

Read more about the symptoms of a dental abscess.

Types and causes of dental abscesses

There are two types of dental abscess:

• periapical abscess – where the abscess forms under the tooth (this is the most common type of dental abscess)
• periodontal abscess – where the abscess forms in the supporting gum and bone

Both types are caused when bacteria build up inside your mouth and usually occurs due to a combination of:

• poor dental hygiene – not cleaning your teeth and gums properly and regularly (read our advice on how to brush and floss your teeth)
• consuming lots of sugary or starchy food and drink – the carbohydrates in these encourage bacteria to grow, causing tooth decay

Read more about the causes of a dental abscess.

Treating dental abscesses

If you think you may have a dental abscess, make a dentist appointment as soon as possible.

There isn’t a lot your GP can do other than recommend painkillers, such as ibuprofen or paracetamol, to help relieve the pain. You can get these over the counter from your local pharmacist.

Treatment varies, depending on what caused the abscess. Generally, treatment involves draining the pus, either with root canal treatment, removing the affected tooth or gum treatment.

This type of treatment should not be too painful, as local anaesthetic will be used to numb the affected area of your mouth.

Unlike some other types of infection, a dental abscess will not get better on its own and must be treated by a dentist. With appropriate treatment, the bacterial infection that causes a dental abscess can usually be cured. Antibiotics are not used to treat a dental abscess, but may occasionally be used to reduce the symptoms.

Read more about how a dental abscess is treated.

Complications of dental abscesses

Complications are rare, but can be serious. For example, the infection may spread to a nearby bone (osteomyelitis).

Read more about the complications of a dental abscess.

Finding an NHS dentist

If you are not registered with an NHS dentist, there are a number of options available to you:

• use the NHS Choices health services post code search to find a dentist in your area
• call NHS 111 to request details of dental services in your area
• text the word “dentist” to 64746 or NHSGO from your mobile phone from the area you need a dentist
• get in touch with your local clinical commissioning group (CCG) to find out about the dental access helpline

Emergency treatment

If you are in severe pain, you may need emergency out-of-hours dental treatment.

Find out how you can access an NHS dentist in an emergency or out-of-hours.

You may have to pay for your treatment, depending on your circumstances.

Find out more about NHS dental services.

The main symptom of a dental abscess is an intense, throbbing pain in your affected tooth or gum.

The pain usually comes on suddenly and may gradually get worse over a few hours or a few days.

Sometimes the pain may spread to your ear, lower jaw and neck, on the same side as the affected tooth. There can also be severe swelling in the face, which can spread if the abscess is not treated.

Other symptoms

These can include:

• tenderness of your tooth and surrounding area
• sensitivity to very hot or cold food and drink
• an unpleasant taste in your mouth
• bad breath (halitosis)
• a general feeling of being unwell
• difficulty opening your mouth
• difficulty swallowing (dysphagia)
• disturbed sleep
• a high temperature (fever)

When to seek immediate medical help

The following symptoms may mean the infection has spread to other parts of your body:

• swelling in your face
• a high temperature (fever) of 38°C (100.4°F) or above
• severe pain that does not respond to treatment with painkillers
• breathing difficulties

If you develop any of these symptoms and you are not due to see a dentist straight away, you will need to access NHS emergency dental services. In this situation, you can call:

• your dentist, who should have an answerphone message with details of how to access out-of-hours dental treatment
• the helpline of your local clinical commissioning group (CCG) – you can use the find services directory to find your local CCG
• NHS 111

Alternatively, you could visit the accident and emergency (A&E) department of your local hospital.

The only way to cure a dental abscess is with dental treatment.

Your GP can give you advice, but they cannot provide the treatment needed to cure an abscess.

Your dentist will treat your abscess using dental procedures and, in some cases, surgery (see below).

Painkillers

A dental abscess can be very painful, but you can use over-the-counter painkillers from your local pharmacy to control the pain while you are waiting for dental treatment.

Ibuprofen is the preferred painkiller for dental abscesses, but if you are unable to take it for medical reasons, you can take paracetamol instead.

If one painkiller fails to relieve the pain, taking both paracetamol and ibuprofen at the same time can often work (this is safe for adults, but not for children under 16).

Always read and follow the information on the packet about how much to take and how often, and do not exceed the maximum stated dose.

Accidental overdoses have been reported in people who take too many painkillers when trying to relieve the pain of a dental abscess.

Painkillers cannot treat or cure a dental abscess, so they should not be used to delay dental treatment.

To take painkillers safely, follow this advice:

• do not take ibuprofen if you are asthmatic or if you have a stomach ulcer, or you have had one in the past
• do not take more than one painkiller at a time without first checking with your GP or pharmacist; this can be dangerous, because many over-the-counter products contain similar painkillers and overdosing is possible when combining products
• ibuprofen and paracetamol are both available as liquid preparations for children
• aspirin is not suitable for children under 16 
• if you are pregnant or breastfeeding, you should take paracetamol

Self care

Other self care techniques include:

• avoiding anything that makes the pain worse, such as hot or cold foods or cold air
• holding cooled water or crushed ice around the tooth can sometimes ease the pain
• the pain can often feel worse when you are lying flat, so lying propped up may help ease pain

Dental treatment

Your dentist will first discuss with you which treatment is appropriate. This could be:

• root canal treatment
• removing an affected tooth
• in some cases, surgery 

Antibiotics

Antibiotics are not routinely prescribed to treat dental abscesses because:

• draining the abscess is a more effective treatment
• using antibiotics to treat non-serious infections makes them less effective at treating more serious infections (this is known as antibiotic resistance)

Antibiotics are usually only required if:

• there are signs of severe infection
• there are signs the infection is spreading, such as swelling of your face or neck
• you have a high risk of complications – for example, people with a weakened immune system or diabetes

If antibiotics are needed, an antibiotic called amoxicillin or phenoxymethylpenicillin is usually prescribed. If you are allergic to penicillin, clarithromycin may be prescribed instead.

In cases where the infection is severe or spreading, metronidazole may be prescribed. If you are allergic to metronidazole, clindamycin may be prescribed.

Reoccurring infection

If you have a periapical abscess and your infection returns, you may need to be referred to a specialist for further treatment.

In some cases, a dental abscess infection can reoccur even after dental and surgical procedures. If this happens, or if your tooth is severely broken down, it may need to be removed altogether (extracted).